The present disclosure relates generally to integrated circuits. More particularly, the present disclosure relates to countering security threats created by manipulation of the power supply rails of the integrated circuit.
An increasing number of devices include a system-on-a-chip (SOC), which is a single integrated circuit (chip) that includes a processor, volatile memory, and other components. During operation, the volatile memory may contain secure information such as security algorithms, unencrypted data, cryptographic keys, and the like. A hacker who has gained possession of such a device could gain access to the secure information by manipulating the voltage of the power supply provided to the SOC. For example, the hacker could increase the work load, which would cause the processor of the SOC to increase its operating frequency and voltage. The hacker could then suddenly reduce the voltage, causing the processor to hang because the voltage is insufficient to support the high operating frequency. Once the processor hangs, the hacker could gain access to the secure information in the non-volatile memory by a variety of methods, for example by using a test access port such as a Joint Test Action Group (JTAG) port.